/*
 * Copyright 2009 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.multi.qrcode;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.NotFoundException;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.ResultMetadataType;
import com.google.zxing.ResultPoint;
import com.google.zxing.common.DecoderResult;
import com.google.zxing.common.DetectorResult;
import com.google.zxing.multi.MultipleBarcodeReader;
import com.google.zxing.multi.qrcode.detector.MultiDetector;
import com.google.zxing.qrcode.QRCodeReader;

import java.util.Hashtable;
import java.util.Vector;

/**
 * This implementation can detect and decode multiple QR Codes in an image.
 * 
 * @author Sean Owen
 * @author Hannes Erven
 */
public final class QRCodeMultiReader extends QRCodeReader implements MultipleBarcodeReader {

	private static final Result[] EMPTY_RESULT_ARRAY = new Result[0];

	public Result[] decodeMultiple(BinaryBitmap image) throws NotFoundException {
		return decodeMultiple(image, null);
	}

	public Result[] decodeMultiple(BinaryBitmap image, Hashtable hints) throws NotFoundException {
		Vector results = new Vector();
		DetectorResult[] detectorResult = new MultiDetector(image.getBlackMatrix()).detectMulti(hints);
		for (int i = 0; i < detectorResult.length; i++) {
			try {
				DecoderResult decoderResult = getDecoder().decode(detectorResult[i].getBits());
				ResultPoint[] points = detectorResult[i].getPoints();
				Result result = new Result(decoderResult.getText(), decoderResult.getRawBytes(), points, BarcodeFormat.QR_CODE);
				if (decoderResult.getByteSegments() != null) {
					result.putMetadata(ResultMetadataType.BYTE_SEGMENTS, decoderResult.getByteSegments());
				}
				if (decoderResult.getECLevel() != null) {
					result.putMetadata(ResultMetadataType.ERROR_CORRECTION_LEVEL, decoderResult.getECLevel().toString());
				}
				results.addElement(result);
			} catch (ReaderException re) {
				// ignore and continue
			}
		}
		if (results.isEmpty()) {
			return EMPTY_RESULT_ARRAY;
		} else {
			Result[] resultArray = new Result[results.size()];
			for (int i = 0; i < results.size(); i++) {
				resultArray[i] = (Result) results.elementAt(i);
			}
			return resultArray;
		}
	}
}